Electrochromic devices are today used in widely different applications for enabling control of light transmission. Non-exclusive examples are helmet visors, windows on buildings or automotives, mirrors and goggles. In a typical non-self-erasing electrochromic device, a thin foil of stacked layers is used, incorporating conducting layers, electrochromic layers and an electrolyte layer. In certain embodiments, these layers are provided between two substrate sheets serving as main structural bodies of the electrochromic device. In order to change the transmittance of the device, a voltage is provided between two electron conducting layers. The voltage causes a charging of the electrochromic device, which in turn results in a transmittance change. The level of transmittance is preserved when the voltage is removed.
An important process step in manufacturing of electrochromic devices is the contacting of the electron conducting layers. Since the electrochromic device generally is very thin, so are the electron conducting layers. Contacting from the sides of the electrochromic device becomes practically impossible or at least very difficult to perform in a more or less automated manner. The typical approach for facilitating contacting is to let one substrate sheet with the associated electron conducting layer protrude outside the other substrate sheet in a direction along the extension of the generally sheet-shaped electrochromic device. The other substrate sheet and the other electron conducting layer are typically protruding at another portion of the device. Contacting of the electron conducting layers can then be performed at these protruding portions.
Contacting geometries have therefore to be determined in advance. The deposition of the electrochromic layers or counter electrode layers has to be excluded from such areas. Furthermore, during the lamination process, aligning of the substrate has to be performed in order to ensure that the areas intended for contacting do not become covered. Moreover, if the laminated EC laminate is going to be transported before the actual contacting is performed, the exposed areas may be damaged if not being properly protected.
Also, in different applications, electrochromic devices of varying geometrical shapes may be needed. The final shape may even not be known until just before the actual assembly. In such cases, it can be difficult to provide semi-manufactured electrochromic devices with a correct shape in advance, and it would be beneficial if the final shape of the electrochromic device could be cut out from a larger sheet of an electrochromic layered structure. In such cases, the provision of protruding parts appropriate for contacting becomes even more difficult.